No deaths or injuries have been reported from the tires, which were made as replacement tires for commercial light trucks and full-sized heavy duty vans from April 2010 until early this year, according to the company.

Michelin North America Inc., based in Greenville, S.C., is beginning the recall immediately. Tires will be replaced at no charge. Websites and toll-free numbers have been set up with more information.

Quality-control workers started noticing an increase in reported problems with the tires this year. The company has noticed the separation in less than 150 tires, but decided the voluntary recall was needed to protect the safety of drivers, said Michelin's technical director, Mike Wischhusen.

"We constantly monitor our products performance in the field and it was our own internal quality systems that caught this issue," Wischhusen said. "We caught it very early, based on a very small number of returns."

Michelin's internal testing shows the problems with the tires have apparently been corrected for those manufactured more recently, Wischhusen said.

"A tire is a complex thing. There is rarely one thing you can pinpoint to cause something like this," he said.

The tires being recalled were BFGoodrich commercial tires LT 235/85 and LT245/75 and Uniroyal Laredo tires LT 235/85 and LT245/75.